Measurement of moisture content in a fluidized bed dryer using an electrostatic sensor array

Fluidized bed dryers have been widely applied to dry raw materials or final products due to the advantages of good mixing efficiency and high heat and mass transfer rate. In order to control and optimize the drying process of fluidized bed dryers, it is necessary to develop reliable methods to measure the moisture content of solid particles in the bed. Because of the advantages of non-intrusiveness, simple structure and high sensitivity, an electrostatic sensor array has been developed to monitor the drying process. Experimental investigations were conducted on a lab-scale fluidized bed dryer. The moisture content during the drying process was measured using the sampled particles as reference. It is found that the fluctuation of the electrostatic signals can reflect the change in moisture content. However, the relationship between the fluctuation of the electrostatic signal and the moisture content depends on the air velocity in the dryer. To eliminate the velocity effect on moisture content measurement, a model between the moisture content and the root-mean-square magnitude of the electrostatic signal is established. The effectiveness of the model is validated using experimental results under a range of conditions. The findings indicate that the electrostatic sensor array can measure the moisture content in the bed with a maximum error of ±15%

The Church in Africa as an Agent of Social Transformation through Reconciliation, Justice and Peace in Light of the Second African Synod

This thesis explores the proposals of the Second African Synod on reconciliation, justice and peace. It addresses these challenges in the socio-political, economic and cultural dimensions of African society, proposed by the Second African Synod as central to the present mission of African Christianity. The thesis presents a historical study of the three challenges highlighted in the synod document, and demonstrates how to implement and translate the recommendations of the synod in a concrete pastoral plan in the African setting. This research contends that the Church, while remaining the salt of the earth and light of the world, should engage the various societal structures and institutions, and so help Africa to become a reconciled society where the fruits of justice and peace shall be harvested in abundance. This research demonstrates the possibility of realizing the aspirations of the Second African Synod by employing the common elements that were used by the Truth and Reconciliation Commission of South Africa, which helped foster reconciliation and peace in that country. This study concludes by arguing that, given the varying and peculiar social contexts of most African countries, African Christianity has a major role to play as an instrument of reconciliation, justice and peace in transforming the continent of Africa.Master of Theology (ThM

Feed-Forward Prediction of Product Qualities in Enzymatic Protein Hydrolysis of Poultry By-Products: a Spectroscopic Approach

Enzymatic protein hydrolysis (EPH) is one of the industrial bioprocesses used to recover valuable constituents from food processing by-products. Extensive heterogeneity of by-products from, for example, meat processing is a major challenge in production of protein hydrolysates with stable and desirable quality attributes. Therefore, there is a need for process control tools for production of hydrolysates with defined qualities from such heterogeneous raw materials. In the present study, we are reporting a new feed-forward process control strategy for enzymatic protein hydrolysis of poultry by-products. Four different spectroscopic techniques, i.e., NIR imaging scanner, a miniature NIR (microNIR) instrument, fluorescence and Raman, were evaluated as tools for characterization of the raw material composition. Partial least squares (PLS) models for ash, protein, and fat content were developed based on Raman, fluorescence, and microNIR measurements, respectively. In an effort to establish feed-forward process control tools, we developed statistical models that enabled prediction of end-product characteristics, i.e., protein yield and average molecular weight of peptides (Mw), as a function of raw material quality and hydrolysis time. A multiblock sequential orthogonalised-PLS (SO-PLS) model, where spectra from one or more techniques and hydrolysis time were used as predictor variables, was fitted for the feed-forward prediction of product qualities. The best model was obtained for protein yield based on combined use of microNIR and fluorescence (R2 = 0.88 and RMSE = 4.8). A Raman-based model gave a relatively moderate prediction model for Mw (R2 = 0.56 and RMSE = 150). Such statistical models based on spectroscopic measurements of the raw material can be vital process control tools for EPH. To our knowledge, the present work is the first example of a spectroscopic feed-forward process control for an industrially relevant bioprocess.acceptedVersio